Postgres 16

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create table t(
    a varchar(30) 
    default 'abc'
    not null
);

CREATE TABLE


-- checking what the column looks like...
select table_name, column_name, column_default, is_nullable, character_maximum_length
from information_schema.columns
where table_name = 't';


table_name
column_name
column_default
is_nullable
character_maximum_length


t
a
'abc'::character varying
NO
30



SELECT 1


 -- let me innocently expand the varchar len 
alter table t
alter column a type varchar(40);

ALTER TABLE


-- and checking what the column looks like again...
-- it's fine. totally fine.
select table_name, column_name, column_default, is_nullable, character_maximum_length
from information_schema.columns
where table_name = 't';


table_name
column_name
column_default
is_nullable
character_maximum_length


t
a
'abc'::character varying
NO
40



SELECT 1